题目

先化简，再求值：，其中． 答案：解：原式=··························································································· 1分=···························································································· 3分=····�已知函数，．（1）求函数的最小正周期和单调递增区间；（2）若函数图象上的两点的横坐标依次为,为坐标原点,求的外接圆的面积．